////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2009 Daniel F. Hanson
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
////////////////////////////////////////////////////////////////////////////////

using System.Collections.Generic;

namespace SilverLua.Compiler
{
   internal class NamedVariableNode : VariableNode
   {
      internal Symbol Variable { get; private set; }
      
      internal NamedVariableNode(Symbol variable)
      {
         Variable = variable;
      }

      internal override void GenerateAssign(EvaluateNode expr, Parser parser, int currentChunk)
      {
         if (Variable.IsLocal)
         {
            EvaluateNode var = Variable.Resolve();
            parser.ChunkList[currentChunk].Add(new Instruction(Opcode.Move,
                                                               new[] { var.OperandType,
                                                                       expr.OperandType },
                                                               new[] { var.OperandValue,
                                                                       expr.OperandValue }));
         }
         else
         {
            parser.ChunkList[currentChunk].Add(new Instruction(Opcode.SetGlobal,
                                                               new[] { OperandType.StringLiteral,
                                                                       expr.OperandType },
                                                               new[] { parser.ChunkList[currentChunk].ResolveString(Variable.Name),
                                                                       expr.OperandValue }));
         }
      }

      internal override EvaluateNode Evaluate(Parser parser, int currentChunk)
      {
         EvaluateNode register;
         
         if (Variable.IsLocal)
         {
            register = Variable.Resolve();
         }
         else
         {
            register = new EvaluateNode { OperandType = OperandType.Value,
                                          OperandValue = parser.ChunkList[currentChunk].AllocateTempRegister() };
            
            parser.ChunkList[currentChunk].Add(new Instruction(Opcode.GetGlobal,
                                                               new[] { register.OperandType,
                                                                       OperandType.StringLiteral },
                                                               new[] { register.OperandValue,
                                                                       parser.ChunkList[currentChunk].ResolveString(Variable.Name) }));
         }
         
         return register;
      }

      internal override void EvaluateTo(int register, Parser parser, int currentChunk)
      {
         if (Variable.IsLocal)
         {
            EvaluateNode var = Variable.Resolve();
            
            parser.ChunkList[currentChunk].Add(new Instruction(Opcode.Move,
                                                               new[] { OperandType.Value,
                                                                       var.OperandType },
                                                               new[] { register,
                                                                       var.OperandValue }));
         }
         else
         {
            parser.ChunkList[currentChunk].Add(new Instruction(Opcode.GetGlobal,
                                                               new[] { OperandType.Value,
                                                                       OperandType.StringLiteral },
                                                               new[] { register,
                                                                       parser.ChunkList[currentChunk].ResolveString(Variable.Name) }));
         }
      }
   }
}
